Methods and systems for making telephone calls

ABSTRACT

Embodiments of the present invention relate to methods and systems for making a call. Such methods and systems may request the call using a network, initiate a first leg to a caller device based on the request, initiate a second leg to a receiver device based on the request, connect the first leg and the second leg to make the call, and bill the call to a account associated with the subscriber.

RELATED APPLICATIONS

This is a continuation of application Ser. No. 10/317,937, filed Dec.12, 2002, now U.S. Pat. No. 7,251,317 which claims benefit of U.S.Provisional Application No. 60/347,608, entitled “Method forClick-to-Talk Service that Utilizes a Converged VOIP and PSTNIntelligent Network,” filed Jan. 10, 2002, both of which are expresslyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to the field of communicationsand, more particularly, relates to methods, systems, and articles ofmanufacture for making telephone calls.

BACKGROUND OF THE INVENTION

Various applications (including Web-based applications, softwareapplications, hardware applications, services, etc.) may allow a user tomake a telephone call from a Public Switched Telephone Network (PSTN)telephone to another PSTN telephone using an Internet Protocol (IP)network. However, these applications are typically limited in severalways. For example, some applications may be limited to placing callsfrom an enterprise to a customer (or a potential customer) of theenterprise and effectively serve simply as an equivalent to a toll-freenumber called by the (potential) customer. Other applications may beadapted to connect any two telephones, but can not bill the calldirectly to either telephone. Instead, the call may be billed to acredit card or some other account held by the caller, called party(receiver), or other party.

Some applications may use “softswitch” technology to handle most of theswitching in the IP network and use IP_PSTN gateways to extend each legof a call to the PSTN telephones. In such cases, the IP network may actas an interexchange carrier (IXC) and, therefore, preclude the use of acustomer's preferred IXC.

These limitations and others restrict the use of these applications andmake them inconvenient for customers or subscribers. Prior applicationsalso consume significantly more network resources than a call madedirectly from the caller to the receiver. In view of these drawbacks, itwould be beneficial to provide for an IP-stimulated initiation of aPSTN-to-PSTN call that can be billed directly to a subscriber's PSTNtelephone and that can consume minimal network resources.

SUMMARY OF THE INVENTION

Methods, systems, and articles of manufacture of the present inventionmay be adapted to consume minimal network resources to initiate aPSTN-to-PSTN call. Further, in accordance with embodiments of theinvention, such calls may be billed directly to a PSTN telephoneaccount.

One exemplary embodiment of the invention relates to a method for makingcalls. The method may include: receiving a request to make a call from afirst network; initiating a first leg to a caller device based on therequest; initiating a second leg to a receiver device based on therequest; connecting the first leg and the second leg to make the call;and billing the call to a subscriber's telephone account on the secondnetwork.

Another exemplary embodiment of the invention relates to a method forsubstituting a subscriber number. The method may include: specifying thesubscriber number in a setup message; sending a query message when thesetup message triggers a setup trigger; recognizing a calling partyidentification; and sending a response message. The query message maycontain the subscriber number and at least one of the calling partyidentification and a charge number. The response message may contain thesubscriber number substituted in the at least one of the calling partyidentification and the charge number.

Yet another exemplary embodiment of the invention relates to anothermethod for making a call. The method may include: receiving a request tomake the call using a first network; delivering the request from thefirst network to a second network; initiating, over the second network,a first leg to a caller device based on the request; forwarding, overthe second network, a second leg to a receiver device; connecting, overthe second network, the first leg and the second leg to make the callbetween the caller device and the receiver device; and billing the callto a subscriber's telephone account on the second network.

Another exemplary embodiment of the invention relates to still anothermethod for making a call. The method may include: providing a request tomake the call using a first network; delivering the request from thefirst network to a second network; initiating, over the second network,a leg to a caller device based on the request; originating, over thesecond network, the call between a caller device and a receiver devicebased on the request; and billing the call to a subscriber's telephoneaccount on the second network.

Additional embodiments and aspects of the invention are set forth in thedetailed description which follows, and in part are obvious from thedescription, or may be learned by practice of methods, systems, andarticles of manufacture consistent with the scope of the presentinvention. It is understood that both the foregoing general descriptionand the following detailed description are exemplary and explanatoryonly and are not restrictive of the claimed embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of theinvention and together with the description, serve to explain theprinciples of the invention. In the drawings:

FIG. 1 illustrates a first exemplary system, consistent with embodimentsof the present invention, for making a telephone call between PSTNendpoints;

FIG. 2 illustrates a first exemplary method, consistent with embodimentsof the present invention, for making a telephone call between PSTNendpoints;

FIG. 3 illustrates a second exemplary system, consistent withembodiments of the present invention, for making a telephone callbetween PSTN endpoints;

FIG. 4 illustrates a second exemplary method, consistent withembodiments of the present invention, for making a telephone callbetween PSTN endpoints;

FIG. 5 illustrates a third exemplary system, consistent with embodimentsof the present invention, for making a telephone call between PSTNendpoints;

FIG. 6 illustrates an exemplary method, consistent with embodiments ofthe present invention, for substituting a subscriber number;

FIGS. 7A and 7B illustrate a third exemplary method, consistent withembodiments of the present invention, for making a telephone callbetween PSTN endpoints;

FIG. 8 illustrates a fourth exemplary system, consistent withembodiments of the present invention, for making a telephone callbetween PSTN endpoints; and

FIGS. 9A and 9B illustrate a fourth exemplary method, consistent withembodiments of the present invention, for making a telephone callbetween PSTN endpoints.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention relate to methods, systems, andarticles of manufacture for making telephone calls. The exemplarysystems and methods disclosed herein propose several alternatives forimplementing a PSTN-to-PSTN call and for a network protocol to be usedto initiate the call. The initiated call may be billed to a subscriber,consistent with the subscriber's service profile (e.g., services,restrictions, preferences, or features associated with the subscriber).Additionally, the initiated call may be processed such that the callappears to a receiver and/or to the subscriber as if the call initiatedfrom the subscriber's telephone. Also, the initiated call may beprocessed to utilize minimal network resources when making the call.

Reference is now made in detail to exemplary embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are usedthroughout the drawings to refer to the same or like parts.

Some of the exemplary embodiments disclosed herein refer to thefollowing documents and standards, all of which are expresslyincorporated herein by reference in their entireties: AINGR:Switch—Intelligent Peripheral Interface (IPI), Telcordia Technologies,GR-1129-CORE, Issue 4, November 1999; AINGR: Switching Systems,Telcordia Technologies, GR-1298-CORE, Issue 6, November 2000; AINGR:Switch—Service Control Point (SCP)/Adjunct Interface, TelcordiaTechnologies, GR-1299-CORE, Issue 6, November, 2000; GenericRequirements for ISDN PRI Two B-Channel Transfer, TelcordiaTechnologies, GR-2865-CORE, Issue 2, May 1997; SDP: Session DescriptionProtocol, IETF, RFC 2327, April 1998; SIP: Session Initiation Protocol,IETF, RFC 2543, 2001; The PINT Service Protocol, IETF, RFC 2848, June2000; 2000 Version of National ISDN Primary Rate Interface (PRI)Customer Premises Equipment (CPE) Generic Guidelines, TelcordiaTechnologies, SR-4994, Issue 1, December 1999; Switching System GenericRequirements Supporting ISDN Access Using the ISDN User Part, TelcordiaTechnologies, TR-NWT-000444, Issue 3, May 1993; ISDN Primary RateInterface Call Control Switching and Signaling Generic Requirements forClass II Equipment, Telcordia Technologies, TR-NWT-001268, Revision 4,March 1998; Bell Communications Research Specification of SignalingSystem Number 7, Telcordia Technologies, GR-246-CORE, Issue 3, December1998; LSSGR: Switching System Generic Requirements for Call ControlUsing the Integrated Services Digital Network User Part (ISDNUP),Telcordia Technologies, GR-317-CORE, Issue 3, November 1999; and LSSGR:Switching System Generic Requirements for ICI Using the ISDNUP, (AModule of LSSGR, FR-64), Telcordia Technologies, GR-394-CORE, Issue 3,November 1999.

FIG. 1 illustrates an exemplary system 100 for placing a telephone call,consistent with embodiments of the present invention. The system 100 mayinclude a call initiator 102, a network 104, a PSTN 106, a caller device108, and a receiver device 110. The call initiator 102 may be coupled tothe network 104. The network 104 may be coupled to the PSTN 106. Thecaller device 108 and receiver device 110 may be coupled to the PSTN106. As used herein, “coupling” may include direct or indirectconnections between elements. Coupling may involve Ethernet links, SS7,voice trunks, and loops, as described below, or any other connectioncompatible with embodiments of the present invention.

The call initiator 102 may include a computer, software, hardware, orany other component or mechanism for sending a request to communicablyconnect the caller device 108 and the receiver device 110. For example,the call initiator 102 may be a computer, a wireless applicationprotocol (WAP) phone, and/or some other Internet portal, whereby a usermay send a request to initiate a call via an Internet website, an e-mailmessage, an Instant Message, etc. In another example, the user may use acursor to “click” a button or link in a graphical user interface (GUI)presented by the call initiator 102. The “click” may cause the callinitiator 102 to send the request to initiate the call. As part of thisprocess, the user may be required to input or provide information forthe request. Additionally, or alternatively, such information in wholeor in part may be stored and recalled during call initiation. As one ofordinary skill in the art can appreciate, additional techniques andsystems may be used to send or generate the request to initiate thecall.

The request may include various information, including the telephonenumber(s) associated with a subscriber, the caller device 108, and/orthe receiver device 110. The request may be delivered through thenetwork 104 to the PSTN 106. Various protocols may be used to thedeliver the request and initiate the call. Examples of protocols mayinclude the PSTN and Internet Internetworking Working Group (PINT)Service Protocol defined in RFC 2848, as referenced above, the Half-PINTprotocol, the Session Initiation Protocol (SIP), the Session DescriptionProtocol (SDP), extensions of SIP or SDP, and/or any other protocolcompatible with embodiments of the invention.

The network 104 may include an IP network, Asynchronous Transfer Mode(ATM) network, a local area network (LAN), a metropolitan area network(MAN), a wide area network (WAN), the public Internet, a privatenetwork, a virtual private network, an ad hoc network, etc. The network104 may include one or more of wired and/or wireless communications.Wireless communications may include radio transmission via the airwaves,however, those of ordinary skill in the art can appreciate that variousother communication techniques can be used to provide wirelesstransmission including infrared line of sight, cellular, microwave,satellite, Bluetooth packet radio, spread spectrum radio, etc. Wirelessdata may include, but is not limited to, paging, text messaging, e-mail,Internet access, and other specialized data applications specificallyexcluding, or including voice transmission.

The PSTN 106 may be implemented using conventional, circuit switchedlocal and/or long-distance network(s). The PSTN 106 may includeend-office switching systems, local tandem switches, access tandemswitches, Common Channel Signaling System No. 7(SS7) trunks fromend-office to end-office, SS7 trunks from end-office to tandem switches,and SS7 signaling networks which include Signaling Transfer Points(STPs) that route out-of-band signaling between component signalingpoints and SS7 signaling links. By way of a non-limiting example, PSTN106 may be a Verizon telephone network, a local PSTN, a long distancePSTN, etc. As one of ordinary skill in the art can appreciate, the PSTN106 may include one or more combinations of smaller PSTNs.

SS7 is a signaling protocol used to exchange information between networkelements. Depending on its country of implementation, it may refer to astandard for telecommunications defined by the InternationalTelecommunication Union (ITU) Telecommunication Standardization Sector,or a standard defined by Committee T1 of the American National StandardsInstitute. The standards are similar in function, but may differslightly in message encoding. Each standard defines the procedures andprotocol by which network elements in a PSTN exchange information over adigital signaling network to effect wireless and wireline call setup,routing, and control. An SS7 network and protocol can be used for suchservices as basic call setup, management and tear down, local numberportability (LNP), toll-free service, enhanced call features (e.g., callforwarding, calling party name/number display, three-way calling, etc.),efficient and secure worldwide telecommunications, etc.

The caller device 108 and/or the receiver device 110 may be a PSTNtelephone, facsimile machine, modem, or other device/system capable offacilitating communication over a PSTN. Alternatively, the receiverdevice 110 may be an IP telephone, a cellular telephone, or otherdevice/system capable of facilitating communication over an IP network,a cellular network, or any other type of network.

According to an embodiment of the present invention, system 100 of FIG.1 may be configured to partly or wholly implement the exemplary methodin the flowchart 200 of FIG. 2 for the network-stimulated initiation ofa PSTN-to-PSTN call, which can be billed directly to a subscriber's PSTNtelephone number. For example, as illustrated in FIG. 2, a user (notshown) may use the call initiator 102 to initiate a call (step 202).This may involve sending a request to initiate the call as describedabove. The call initiator 102 may send the request through the network104 to the PSTN 106. The PSTN 106 may ring the caller device 108 (step204). When the caller device 108 receives and acknowledges (manually orautomatically) the ring from the PSTN 106, the caller device 108 mayoptionally play a first announcement (step 206). Announcement(s) may bestored on the caller device 108 and played by the caller device 108 orannouncement(s) may be stored outside the caller device 108 (e.g.,stored on and played from the PSTN 106, the network 104, etc.) andrelayed through the caller device 108 (i.e., the caller device 108 mayact as an end station and relay announcements). By way of a non-limitingexample, the first announcement may include a statement indicating thatthe caller device 108 will be used to connect a call initiated by theuser and/or any other relevant information.

After a caller (not shown) acknowledges the call at the caller device108, the call may be extended to the receiver device 110 via the PSTN106 (step 208). During this step, the caller may hear a ring-back toneuntil a called party (not shown) at the receiver device 110 answers.When the receiver device 110 receives and acknowledges the callextension, the receiver device 110 may optionally play a secondannouncement (step 210). Announcement(s) may be stored on the receiverdevice 110 and played by the receiver device 110 or announcement(s) maybe stored outside the receiver device 110 (e.g., stored on and playedfrom the PSTN 106, the network 104, etc.) and relayed through thereceiver device 110 (i.e., the receiver device 110 may act as an endstation and relay announcements). By way of a non-limiting example, thesecond announcement may include a statement indicating that the receiverdevice 110 is currently being used to connect a call and/or any otherrelevant information. The PSTN 106 may then connect the call between thecaller device 108 and the receiver device 110 (step 212). The call maybe connected using any conventional method (switchboard, call routing,etc.) that is compatible with the embodiment of FIG. 2. The callingparty identity presented to the receiver device 110 may be that of thesubscriber's PSTN telephone line, provided Calling Party PresentationRestrictions (CPPRs) do not apply.

Both legs (to the caller device 108 and to the receiver device 110) ofthe connected call may be billed to a subscriber's PSTN telephone line.The subscriber may be the user that initiated the call at step 202, acaller using the caller device 108 to communicate through the connectedcall, a receiver using the receiver device 110 to communicate throughthe connected call, or some other entity subscribing to a service on thePSTN. The subscriber, user, caller, and/or receiver may be the sameentity. The connected call may appear in the billing process as if thesubscriber originated the connected call on his/her PSTN telephone. Inconnecting the call, the system 100 may respect the subscriber's carrierchoices (both intra-Local Access and Transport Area (LATA) andinter-LATA, as appropriate) and all other attributes, services, andfeatures applicable to similar calls from the subscriber's line.

Examples of other attributes, services, and features may include atelephone line's primary inter-exchange carrier, local carrier, class ofservice (e.g., flat rate, measured rate, etc.), toll restrictions,1010XXXX blocking, caller identification blocking, call forwarding,speed calling, voice mail, Advanced Intelligent Network (AIN) services,etc.

In performing the exemplary method illustrated in FIG. 2, system 100 mayensure that the PSTN 106 exclusively carries an initiated call in itsfinal configuration (i.e., when the two legs of the call have beenbridged) using as few network 104 resources as possible. The initiatedcall may utilize additional network 104 resources prior to the time thecaller device 108 and the receiver device 110 are connected together.

In another embodiment of the present invention, an exemplary system 300illustrated in FIG. 3 may be used to initiate a call between two PSTNendpoints. The system 300 may include a computer 302, an IP network 304,a service node (SN) 306, a first service switching point (SSP) 308, acaller telephone 310, a second SSP 312, and a receiver telephone 314.The computer 302 may be coupled to the IP network 304. The IP network304 may be coupled to the SN 306. The SN 306 may be coupled to the firstSSP 308. The first SSP 308 may be coupled to the caller telephone 310and the second SSP 312. The second SSP 312 may be coupled to thereceiver telephone 314. The coupling between the SN 306 and the firstSSP 308 may include, for example, an integrated services digital network(ISDN) primary rate interface (PRI). By way of a non-limiting example,the computer 302, the IP network 304, and the SN 306 may be coupledtogether via an IP connection (e.g., Ethernet cable, fiber cable, etc.).The SSPs 308 and 312 may be connected directly or indirectly by voicetrunks as part of a PSTN. The telephones 310 and 314 may be coupled to alocal end office (e.g., a SSP, etc.) via “loops”. A “loop” may be anymechanism (e.g., a loop of copper wire, an analog loop carrier system, adigital loop carrier system, etc.) that can carry signaling information(e.g., dialed digits, on or off hook, ring phone, etc.) and bearerinformation (e.g., voice conversation, modem tones, etc.) between thelocal end offices 308 and 312 and the telephones 310 and 314.

As one of ordinary skill in the art can appreciate, the computer 302 maybe any device or system that facilitates a user's request to initiate acall. Some examples include: desktop computers; laptops computers;mainframes; application specific electronic/mechanical devices; and/orany other mechanisms that can facilitate the request.

By way of a non-limiting example, service node 306 may include a PSTNelement, capable of receiving calls, that provides specialized servicessuch as collecting account information, playing voice prompts andrecordings, and/or providing various interactive services. Examples mayinclude calling card platforms, voice response units, voice mailsystems, etc.

The SSPs 308 and 312 are end-office switching system(s) that may becapable of performing AIN functions. The SSPs 308 and 312 may be capableof implementing AIN triggers, launching AIN queries, accepting AINresponse messages, and/or continuing with call processing based on anAIN response message. Although FIG. 3 illustrates the SSPs 308 and 312as being separate devices, this is only done in order to demonstratethat this implementation is viable when the telephones 310 and 314 arecoupled to different SSPs. However, this implementation may be equallyeffective in the event that the telephones 310 and 314 are connected toa single SSP.

As illustrated in FIG. 3, system 300 may include the IP network 304, butas one of ordinary skill in the art can appreciate and as previouslyexplained, other types of networks may be used instead. Although thesystem 300 may use caller and receiver telephones 310 and 314, otherPSTN end user devices/systems as described above may be used instead.

According to an embodiment of the present invention, the system 300 maybe configured to implement the exemplary method illustrated in flowchart400 of FIG. 4. For example, a user (not shown) may perform an action toinitiate a user-requested call (step 402). The action may involve theuse of an application (e.g., a Web browser, an e-mail client, etc.) onthe computer 302 to cause the user-requested call to facilitatecommunication between the caller telephone 310 and the receivertelephone 314. The action may include, inter alia, “clicking” a buttonor a link on a Web page using the computer 302. As part of this process,the user may also be required to input or provide information for therequest. Additionally, or alternatively, such information in whole or inpart may be previously stored and recalled during call initiation. Asone of ordinary skill in the art can appreciate, additional techniquesand systems may be used to send or generate the call request.

Once the call request is made by the user, the IP network 304 maydeliver the request to the SN 306 (step 404). The SN 306 may initiate afirst SN call to a PSTN endpoint, the caller telephone 310 in thisexample (step 406). When the user or a caller answers the first SN call,the SN 306 may play an appropriate announcement, if any (step 408). TheSN 306 may then initiate a second SN call to another PSTN endpoint, thereceiver telephone 314 in this example (step 410). The second SN callmay be initiated using a subscriber's carrier choice that is applicableto the user-requested call. If the subscriber is the same entity as theuser or the caller, the SN 306 may initiate the second SN call using theuser's carrier choice or the caller's carrier choice, respectively. Thesubscriber's telephone number may be used as the calling party numberwhen the SN 306 calls the receiver telephone 314. If an announcement isto be played to a receiver, the SN 306 may play the announcement whenthe receiver answers the second SN call on the receiver telephone 314(step 412). The announcements played to the caller and the receiver maybe the same or different. The SN 306 may connect the first and second SNcalls (one to the caller telephone 310 and one to the receiver telephone314) together at SSP 308 before or after the receiver answers the secondSN call to the receiver telephone 314 (step 414). As one of ordinaryskill in the art can appreciate, the two SN calls may be connectedusing, for example, Two B-Channel Transfer as described in GR-2865-CORE,referenced above.

The Two B-Channel Transfer may be used at step 414 to connect the two SNcalls together without consuming resources related to the SN 306 (i.e.,the SN can be removed from the completed call path after the two callsare connected). If the Two B-Channel Transfer is not used, the SN 306could internally connect the two SN calls for the duration of theuser-requested call. However, the use of Two B-Channel Transfer releasesthose B channels at the point where the SN 306 has no need of furtherinvolvement in the user-requested call, which allows the SN 306 to beprovisioned with fewer B channels to serve a given call volume. If theSN 306 removes itself from further involvement in the user-requestedcall after connecting the two SN calls, then the SN 306 may either playan announcement to the receiver before removing itself or forego playingthe announcement.

In order to ensure that the user-requested call appears to the billingprocess as if the subscriber originated the call on his/her PSTNtelephone (not necessarily shown) and that the calling line identitypresented to the receiver telephone 314 is that of the subscriber's PSTNtelephone, the SN 306 may specify the subscriber's telephone number asthe calling party number in the SETUP message that initiates the secondSN call to the receiver telephone 314 at step 406. SSPs 308 and 312 mayaccept that subscriber number as valid for calling line identificationand billing purposes. Ordinarily, an SSP that meets the requirements ofTR-NWT-001268, as referenced above, will accept as valid only asubscriber number that is explicitly configured at the SSP as valid forthe SN's PRI. Therefore, the subscriber number may be assigned to thesubscriber line, not to the SN's PRI, and hence would not be accepted asvalid when sent by the SN. This may prevent the user-requested call fromappearing to the billing process as if the subscriber originated thecall on his/her PSTN telephone and presenting the desired caller lineidentity to the receiver telephone 314, provided that CPPRs do notapply. However, Section 11.1.1.9 of SR-4994 (2000 NI PRI CPE GenericGuidelines), as referenced above, describes a service called Delivery ofUser Provided Not Screened Calling Party Numbers (CPNs) that canfacilitate exactly the kind of application under consideration here.Under this application, a subscriber-provided unscreened caller numbermay be accepted as valid, and treated as a PSTN-provided caller number.

Further, in order to ensure the user-requested call utilizes thesubscriber's applicable carrier choice (both intra- and/or inter-LATA,as appropriate), the SN 306 may specify the subscriber's carrier choicein the SETUP message that initiates the second SN call to the receivertelephone 314. An SSP meeting the requirements of TR-NWT-001268 permitsthe SN 306 to do so via the Transit Network Selection informationelement in the SETUP message. In order to do this, the SN 306 may beprovisioned with the subscriber's carrier choices and may be able toanalyze the receiver telephone's 314 number to determine the appropriatecarrier (e.g., inter-LATA, intra-LATA toll or local, etc.).

In addition to the subscriber's carrier choices, the SN 306 may alsorespect other attributes, features and services that affect calls madeto and from the subscriber's line. For example, if the subscriber's linehas toll restrictions, the second SN call from the SN 306 to thereceiver telephone 314 may have to be screened consistently with therestrictions on the subscriber's line. The SN 306 may be provisionedwith all relevant attributes of the subscriber's line. The SN 306 maytake all relevant service and feature interactions into account.Further, if the subscriber line has a caller identification (ID)blocking feature, then the SN 306, SSP 308, and SSP 310 may not send ordisplay the caller identification when calling or connecting thereceiver telephone 314. The SN 306 may set a privacy indicator or someother parameter on the call to the receiver telephone 314 or whenconnecting the two SN calls.

Three potential problems arise if the SN 306 is not served by an SSPthat serves the subscriber and/or caller lines. First, the first SN callfrom the SN 306 to the caller telephone 310 might cross rate centerboundaries that would ordinarily make it billable. In suchcircumstances, additional arrangements, such as not billing the first SNcall, would have to be made. Second, the second SN call might be billedat a different rate than it would have if it had actually originated atthe caller telephone 310. In such circumstances, other arrangements,such as billing the second SN call as though it originated at the firstSSP 308 serving the caller, may have to be made to properly bill thesecond SN call. Third, the second SN call from the SN 306 to thereceiver telephone 314 might transit to the carrier's network through anaccess tandem different from the one that would have been used had theuser-requested call originated from the caller telephone 310. In suchcircumstances, the carrier may block the call because the receivertelephone 314 number is not valid for the access tandem. Therefore, thefirst SSP 308 serving the SN 306 may route the second SN call to thesubscriber's carrier through a path (not shown) from which the carrierwill not block the user-requested call.

According to another embodiment of the present invention, the second SSP312 in system 300 may not be a AIN-capable end office (e.g., an SSP)because an AIN feature (e.g., a termination-attempt trigger, a channelsetup trigger, etc.) may not be required at the receiver telephone endto connect a call between the caller telephone 310 and the receivertelephone 314. Instead of SSP 312, a non-AIN-capable end office may becoupled to the SSP 308 (e.g., via a voice trunk, a data trunk, etc.) andto the receiver telephone 314 (e.g., via an analog loop carrier system,a digital loop carrier system, etc.).

In another embodiment of the present invention, the exemplary system 500in FIG. 5 may be used to initiate a call between two PSTN endpoints. Thesystem 500 includes all the elements 302-314 of system 300 with theaddition of a service control point (SCP) 502. The SCP 502 may be anyAIN entity that performs service control functionality. The SCP 502 maycontain the service logic execution environment where AIN services maybe deployed. The service logic may process and respond to an AIN queryfrom other entities, such as an SSP. SCP 502 may be coupled to an SSP(i.e., SSPs 308 and 312). By way of a non-limiting example, the SCP 502may be coupled to the SSP 308 via an SS7 common channel network, an IPnetwork, an ATM network, or other mechanism capable of passing SS7messages from one end-point to another end-point.

According to an embodiment of the present invention, the system 500 maybe used to implement the exemplary method illustrated in the flowchart400 of FIG. 4 in the same manner as described above for system 300, withthe exception that the system 500 may take advantage of AIN capabilitiesto specify the subscriber number. More particularly, instead of relyingupon the first SSP 308 to accept the subscriber number passed by the SN306 as described above for the method in flowchart 400, the SCP 502 mayuse an AIN feature based on a channel setup trigger to perform thesubscriber number substitution.

For example, the system 500 may implement steps 402-408 as previouslydescribed for system 300, but when the SN 306 makes the second SN callto the receiver telephone 314 at step 410 in FIG. 4, the system 500 mayimplement the exemplary method illustrated in the flowchart 600 of FIG.6 to use the subscriber number as the calling party number. Consistentwith an embodiment of the present invention, the SN 306 may specify thesubscriber number as the calling party number in the SETUP message thatinitiates the second SN call (step 602). The SN 306's PRI channels maybe provisioned with a Channel_Setup_PRI trigger. The second SN call mayencounter the Channel_Setup_PRI trigger at SSP 308 (step 604) and causeSSP 308 to send a Query Package to the SCP 502 (step 606). This step maybe performed because the calling party number supplied by the SN 306will have failed screening or not have been screened. The first SSP 308may perform the calling party number screening as specified inTR-NWT-001268, referenced above.

The Query Package sent to the SCP 502 may contain an Info_CollectedTDP-Request Message, which may be populated with CallingPartyID,ChargeNumber, and GenericAddress parameters. The CallingPartyID maycontain the number assigned to the SN 306. The ChargeNumber may containthe SN's 306 charge number. The GenericAddress may include aGenericAddressList parameter which may contain the calling party number(i.e., subscriber number) supplied by the SN 306 as a SupplementalUser-Provided-Not-Screened or User-Provided-Failed-Screening number. TheGenericAddress may be populated as specified in GR-1298-CORE Section4.5.3.2, as referenced above, based on the calling party numberscreening.

The SCP 502 may recognize the CallingPartyID as that of the SN's 306 andmay extract the subscriber number from the GenericAddress (step 608).The SCP 502 may return a Response Package to the first SSP 308 (step610). The Response Package may contain an Analyze_Route message for thefirst SSP 308. The Analyze_Route message may be populated withChargeNumber and CallingPartyID parameters, each containing thesubscriber number. The first SSP 308 may resume processing the second SNcall with the subscriber number specified as the calling party numberand the charge number, and with the carrier specified by the SN 306.Following step 610, the system 500 may proceed to implement, forexample, the remaining steps 412-414 in FIG. 4. Thus, other than themethod for handling the calling party number described above with theflowchart 600, the system 500 may implement flowchart 400 to make auser-requested call as previously described.

In another embodiment of the present invention, the system 500 may beimplemented to perform the exemplary method in flowchart 700 of FIGS. 7Aand 7B. For example, in order to initiate a call between two PSTNendpoints, a user may first make a request to initiate a call using thecomputer 302 (step 702). The IP network 304 may deliver the request tothe SN 306 via the IP network 304 (step 704). In response to therequest, the SN 306 may initiate a first SN call to a caller number ofthe caller telephone 310 (step 706). The caller number may beprovisioned with a Termination_Attempt trigger. The first SN call mayencounter the Termination_Attempt trigger at the first SSP 308 (step708) and may cause the first SSP 308 to send a first Query Package tothe SCP 502 (step 710). The first Query Package may contain a firstTermination_Attempt TDP-Request message, which may be populated withCallingPartyID, CalledPartyID, and RedirectingPartyID parameters. TheCallingPartyID may contain the number assigned to the SN 306. TheCalledPartyID may contain the caller number. The RedirectingPartyID maybe omitted from the Termination_Attempt TDP-Request message.

The SCP 502 may recognize the SN 306 number in the CallingPartyID andobserve that the RedirectingPartyID is omitted (step 712). The omissionmay be used to indicate that the first SN call is to be allowed tocomplete to the caller telephone 310. The SCP 502 may send a firstResponse package to the first SSP 308 (step 714). The first Responsepackage may contain an Authorize_Termination message, which is notpopulated with any parameters that would alter the processing of thefirst SN call. The first SSP 308 may complete the first SN call to thecaller telephone 310 (step 716). When the caller device 310 answers thefirst SN call, the SN 306 may play an appropriate announcement, if any(step 718).

The SN 306 may then initiate a second SN call to the caller telephone310 using a SETUP message (step 720). The SN 306 may specify thereceiver telephone 314 number in the RedirectingNumber parameter of theSETUP message. The second SN call may encounter the Termination_Attempttrigger at the first SSP 308 (step 722), and may cause SSP 308 to send asecond Query package to the SCP 502 (step 724). The CallingPartyID,CalledPartyID, and RedirectingPartyID parameters in the second Querypackage may contain the number assigned to the SN 306, the subscribernumber, and the receiver telephone 314 number supplied by the SN 306,respectively.

The SCP 502 may recognize the SN 306 number and extract the receivertelephone 314 number from the RedirectingPartyID (step 726). The SCP 502may send a second Response Package to the first SSP 308 (step 728). Thesecond Response Package may contain a Forward_Call message, which may bepopulated with CallingPartyID, CalledPartyID, and RedirectingPartyIDparameters. The CallingPartyID, CalledPartyID, and RedirectingPartyIDparameters of the Forward_Call message may contain the subscribernumber, the receiver telephone 314 number, and the subscriber number,respectively.

The first SSP 308 may forward the second SN call to the receivertelephone 314 via the second SSP 312 using the subscriber's carrier asprovisioned in the first SSP 308, while respecting all relevantattributes, services, and features associated with the subscriber's line(step 730). If an announcement is to be played, the SN 306 may play theannouncement when the receiver telephone 314 answers the second SN call(step 732). The SN 306 may connect the first and second SN calls at thefirst and second SSPs 308 and 312 using Two B-Channel Transfer (step734) and may remove itself from the call path.

The exemplary method in the flowchart 700 may not require the SN 306 tobe provisioned with the subscriber's carrier choices and may not need toanalyze the called party number to determine which carrier isapplicable. Further, the SN 306 may not need to be provisioned with anyother attributes of the subscriber because the attributes provisioned atthe first SSP 308 may be used to screen the first and second SN callsfor potential toll restrictions and other telephone line options. Also,this method may place two SN calls from the SN 306 to the first SSP 308.If the SN 306 is served by an SSP other than the first SSP 308, then thetwo SN calls may be processed such that they are not billed.

A variation of the exemplary method in the flowchart 700 may beimplemented in which a GenericAddress parameter is used instead of theRedirectingPartyID parameter. In this variation, the second SN call mayspecify the receiver telephone 314 number as the CallingPartyNumber inthe SETUP message. The receiver telephone 314 number may fail the firstSSP 308 screening and thus appear in the Termination_Attempt TDP-Requestmessage as a GenericAddress in a similar manner to that described abovefor the flowchart 600 of FIG. 6. The SCP 502 may then examine theGenericAddress instead of the RedirectingPartyID to extract the receivertelephone 314 number. If the SSP serving the SN 306 is not the first SSP308, then the SSP serving the SN 306 may be interconnected to SSP 308via SS7 and may pass the GenericAddress to SSP 308, as specified inTR-NWT-000444, referenced above.

In another embodiment of the present invention, the exemplary system 800illustrated in FIG. 8 may be used to initiate a call between two PSTNendpoints. As shown in FIG. 8, the system 800 may include a computer302, an IP network 304, an SCP 502, a first SSP 308, a caller telephone310, a second SSP 312 and a receiver telephone 314. The computer 302 maybe coupled to the IP network 304. The IP network 304 may be coupled tothe SCP 502. The first SSP 308 may be coupled to the SCP 502, callertelephone 310, and the second SSP 312. The second SSP 312 may be coupledto the receiver telephone 314. By way of a non-limiting example, the IPnetwork 304 may be coupled to the SCP 502 via an IP connection (e.g.,Ethernet cable, fiber cable, etc.).

According to an embodiment of the invention, the system 800 may beimplemented to perform the exemplary method in flowchart 900 of FIGS. 9Aand 9B. For example, a user (not shown) may make a request to initiate acall using the computer 302 (step 902). The IP network 304 may deliverthe request to the SCP 502 (step 904). The SCP 502 may send a QueryPackage to the first SSP 308 (step 906). The Query Package may contain aCreate_Call message as specified, for example, in Section 5.9 ofGR-1298-CORE. The Create_Call message may be populated withCallingPartyID and CalledPartyID parameters, which may contain thecaller telephone 310 number and the receiver telephone 314 number,respectively. The Query Package may also contain aRequest_Report_BCM_Event message. The Request_Report_BCM_Event messagemay be populated with an EDP-Request parameter, which may specify theOrigination_Attempt event.

The first SSP 308 may notify the caller telephone 310 line (step 908).The first SSP 308 may perform such notification by, for example,applying power ringing to a non-ISDN line or sending a NOTIFY message toan ISDN line. The first SSP 308 may start a timer to await a callerresponse and may arm the Origination_Attempt EDP-Request. A caller mayrespond to the notification by going off-hook on the caller telephone310 (step 910). When the first SSP 308 detects the caller telephone 310off-hook indication or other response, the first SSP 308 may send afirst Conversation Package to the SCP 502 (step 912). The firstConversation Package may contain an Origination_Attempt EDP-Requestmessage.

In response to the first Conversation Package, the SCP 502 may send asecond Conversation Package to the first SSP 308 (step 914). The secondConversation Package may contain a Send_To_Resource message as specifiedin Section 5.5.3 of GR-1298-CORE. The Send_To_Resource message may bepopulated with parameters that specify an Intelligent Peripheral (IPe)address and announcement identification. The first SSP 308 and an IPe(not shown) may interact as specified in GR-1129-CORE (referenced above)to connect the caller telephone 310 to the IPe and play any identifiedannouncement (step 916). When the IPe finishes playing the announcement,the first SSP 308 may disconnect the caller telephone 310 from the IPeand send a third Conversation Package to the SCP 502 (step 918). Thethird Conversation Package may contain a Resource_Clear message.

The SCP 502 may then send a fourth Conversation Package to the first SSP308 (step 920). The fourth Conversation Package may contain anAnalyze_Route message and a Request_Report_BCM_Event message. TheAnalyze_Route message may not be populated with any routing parameters.The Request_Report_BCM_Event message may be populated with anEDPNotification, which may specify O_Answer and O_Disconnect_Calledevents. The first SSP 308 may proceed to connect the user-requested callfrom the caller telephone 310 to the receiver telephone 314 and may armthe O_Answer and O_Disconnect_Called EDPs (step 922). TheO_Disconnect_Called EDP may be armed to keep an extended transactionopen after the receiver telephone 314 answers. When the receivertelephone 314 answers, the second SSP 312 may send a fifth ConversationPackage to the SCP 502 (step 924). The fifth Conversation Package maycontain an O_Answer EDP-Notification message.

The SCP 502 may send a sixth Conversation Package to the second SSP 312(step 926). The sixth Conversation Package may contain aSend_To_Resource message, which may be populated with parameters thatspecify an IPe address and announcement identification as well as aPartyID and PartyOnHold parameters. The PartyID and PartyOnHold mayspecify “calledparty” and “present”, respectively. The second SSP 312may place the caller telephone 310 on hold, connect the receivertelephone 314 to an IPe (not shown), and interact with the IPe asspecified in GR-1129-CORE to play any identified announcement (step928).

When the IPe finishes playing the announcement, the second SSP 312 maydisconnect the receiver telephone 314 from the IPe, reconnect the callertelephone 310 to the receiver telephone 314, and send a seventhConversation Package to the SCP 502 (step 930). The seventh ConversationPackage may contain a Resource_Clear message. In reply, the SCP 502 maysend a Response Package to the second SSP 312 (step 932). The ResponsePackage may contain a Close message.

If no announcement is to be played to the caller telephone 310, thensteps 914 to 916 may be omitted from the method in flowchart 900. If noannouncement is to be played to the receiver telephone 314, then aResponse Package may be sent at step 920 instead of the fourthConversation Package and steps 924 to 932 may be omitted. The ResponsePackage may contain a Continue message. If neither announcement is to beplayed, the Query Package sent at step 906 may omit theRequest_Report_BCM_Event message, the first SSP 310 may send a ResponsePackage to the SCP 502 at step 912 instead of the first ConversationPackage, and steps 914 to 920 and 924 to 932 may be omitted. TheResponse Package may contain a Close Message.

In the foregoing description, various methods, systems, and articles ofmanufacture are described to invoke a telephone call between two PSTNendpoints as a result of activities in a separate network (e.g., IP,ATM, LAN, Internet, etc.). However, if the telephone call can beinitiated from any point on a network, obvious security problems mayexist. Unrestricted access would permit accidental or maliciousplacement of calls on behalf of subscribers who have not authorized suchcalls. Therefore, sufficient authentication procedures known in the artand compatible with embodiments of the present invention may beincorporated to ensure that only authorized subscribers are able toinitiate calls from authorized telephone lines, etc.

In addition, the invention is not limited to the particulars of theembodiments disclosed herein. For example, the individual features ofeach of the disclosed embodiments may be combined or added to thefeatures of other embodiments. In addition, the steps of the disclosedmethods herein may be combined or modified without departing from thespirit of the invention claimed herein.

Also in the foregoing description, various features are grouped togetherin various embodiments for purposes of streamlining the disclosure. Thismethod of disclosure is not to be interpreted as reflecting an intentionthat the claimed invention requires more features than are expresslyrecited in each claim. Rather, as the following claims reflect,inventive aspects may lie in less than all features of a singleforegoing disclosed embodiment. Thus, the following claims are herebyincorporated into this description, with each claim standing on its ownas a separate embodiment of the invention.

1. A method for making a call that is billed to a subscriber's telephoneaccount, comprising: receiving a request to make the call on apacket-switched network; delivering the request from the packet-switchednetwork to a circuit-switched network; initiating, over thecircuit-switched network, a first leg of the call to a caller devicebased on the request; forwarding, over the circuit-switched network, asecond leg of the call to a receiver device; specifying a subscriber'snumber in a setup message for the second leg of the call; sending aquery message when the setup message triggers a setup trigger, the querymessage containing the subscriber's number and at least one of a callingparty identification and a charge number; sending a response messagecontaining the subscriber's number substituted in the at least one ofthe calling party identification and the charge number; connecting, overthe circuit-switched network, the first leg and the second leg to makethe call between the caller device and the receiver device; and billingthe call requested on the packet-switched network to the subscriber'stelephone account on the circuit-switched network.
 2. The method ofclaim 1, wherein the caller device's telephone number is provisionedwith a termination-attempt trigger, wherein initiating the first legincludes sending a second query message when the termination-attempttrigger is triggered, wherein the second query message contains thecaller device's number and a calling party identification, and whereinthe query message omits a redirecting party identification.
 3. Themethod of claim 1, wherein the method further comprises initiating thesecond leg of the call to the caller device, wherein the caller device'stelephone number is provisioned with a termination-attempt trigger,wherein initiating the second leg includes sending a second querymessage when the termination-attempt trigger is triggered and whereinthe second query message contains a subscriber's number, a calling partyidentification, and the receiver device's number.
 4. The method of claim1, wherein the request includes at least one of a telephone number of asubscriber's telephone line, a telephone number of the caller device,and a telephone number of the receiver device.
 5. The method of claim 1,wherein the call conforms to a subscriber's caller identificationrestriction and does not provide the subscriber's identification to thereceiver device.
 6. The method of claim 1, wherein billing comprisesbilling the call as if the subscriber originated the call on asubscriber's telephone line.
 7. The method of claim 1, wherein themethod further comprises providing a calling identity to the receiverdevice that indicates a subscriber's telephone line.
 8. The method ofclaim 1, wherein the caller device is associated with a caller andwherein the caller and the subscriber are the same entity.
 9. A methodfor making a call that is billed to a subscriber's telephone account,comprising: providing a request to make the call using a packet-switchednetwork; delivering the request from the packet-switched network to acircuit-switched network; initiating, over the circuit-switched network,a leg of the call to a caller device based on the request; specifying asubscriber's number in a setup message for the leg of the call; sendinga query message when the setup message triggers a setup trigger, thequery message containing the subscriber's number and at least one of acalling party identification and a charge number; sending a responsemessage containing the subscriber's number substituted in the at leastone of the calling party identification and the charge number;originating, over the circuit-switched network, the call between acaller device and a receiver device based on the request; and billingthe call requested on the packet-switched network to the subscriber'stelephone account on the circuit-switched network.
 10. The method ofclaim 9, wherein initiating the call includes sending a second querymessage and wherein the second query message contains a create callmessage.
 11. The method of claim 9, wherein initiating the leg includesnotifying the caller device with at least one of a power ring and anotify message.
 12. The method of claim 9, wherein the method furthercomprises sending a conversation message, wherein the conversationmessage contains an Intelligent Peripheral's address and an announcementidentification.
 13. The method of claim 9, wherein originating the callarms at least one of an answer event and a disconnect called event. 14.The method of claim 9, wherein the method further comprises sending aconversation message, wherein the conversation message contains at leastone of an Intelligent Peripheral's address, an announcementidentification, a party identification, and a party on hold parameter.15. The method of claim 9, wherein the call conforms to a subscriber'scaller identification restriction and does not provide the subscriber'sidentification to the receiver device.
 16. The method of claim 9,wherein billing comprises billing the call as if the subscriberoriginated the call on a subscriber's telephone line.
 17. The method ofclaim 9, wherein the method further comprises providing a callingidentity to the receiver device that indicates a subscriber's telephoneline.
 18. A method for making a call that is billed to a subscriber'stelephone account, comprising: sending a request to make the call on apacket-switched network, wherein the request is delivered from thepacket-switched network to a circuit-switched network and wherein therequest initiates, over the circuit-switched network, a first leg of thecall to a caller device; completing the first leg, wherein the first legis connected, over the circuit-switched network, to a forwarded secondleg of the call to make the call between the caller device and areceiver device and wherein the call requested on the packet-switchednetwork is billed to the subscriber's telephone account on thecircuit-switched networks; specifying a subscriber's number in a setupmessage for the second leg of the call; sending a query message when thesetup message triggers a setup trigger, the query message containing thesubscriber's number and at least one of a calling party identificationand a charge number; and sending a response message containing thesubscriber's number substituted in the at least one of the calling partyidentification and the charge number.
 19. The method of claim 18,wherein the caller device is associated with a caller and wherein thecaller and the subscriber are the same entity.
 20. A method for making acall that is billed to a subscriber's telephone account, comprising:providing a request to make the call using a packet-switched network,wherein the request is delivered from the packet-switched network to acircuit-switched network, wherein the request initiates, over thecircuit-switched network, a leg of the call to a caller device, andwherein the request originates, over the circuit-switched network, thecall between the caller device and a receiver device; specifying asubscriber's number in a setup message for the leg of the call; sendinga query message when the setup message triggers a setup trigger, thequery message containing the subscriber's number and at least one of acalling party identification and a charge number; sending a responsemessage containing the subscriber's number substituted in the at leastone of the calling party identification and the charge number; andcompleting the call, wherein the call requested on the packet-switchednetwork is billed to the subscriber's telephone account on thecircuit-switched network.
 21. The method of claim 20, wherein the callerdevice is associated with a caller and wherein the caller and thesubscriber are the same entity.